Gas chromatography entails the analytical separation of a vaporized or gas-phase sample that is injected into a chromatographic column. The column is typically housed in a thermally controlled oven. A chemically inert carrier gas, such as hydrogen, helium or nitrogen, is typically utilized as the mobile phase for elution of the analyte sample in the column. The carrier gas is typically introduced into the column at a location near where the sample is injected, e.g., at the head of the column, and thus carries the sample through the column. The type of analyte detector employed with the gas chromatographic (GC) system often dictates the particular carrier gas utilized. Hydrogen is often a desirable choice for many GC systems for various reasons such as ensuring good sensitivity of the detector employed, such as a flame ionization detector (FID). Hydrogen, however, is a combustible gas with a lower explosion level (LEL) of 4% (40,000 ppm). While hydrogen diffuses rapidly in open air, GC ovens are airtight as well as thermally isolated. Accordingly, in the case of a hydrogen leak inside the GC oven, there is a risk that the hydrogen level may ramp up enough to cause an explosion.
In view of the foregoing, there is a need for a system for detecting leakage of combustible gases such as hydrogen in GC ovens, for enabling fail-safe operation of GC systems in which the use of a combustible gas as a GC carrier gas is desirable, and for preventing such leakage from causing a dangerous condition such as an explosion.